Devastated Veronica Howe wept outside the Central Criminal Court after David Wilson (22), of Marigold Avenue, Darndale, was sentenced for the manslaughter of her son Paul (22).

Mr Howe, of Glenshane Crescent, Tallaght, died following an attack outside a SuperValu store two years ago. He was stabbed in a car park at the rear of the supermarket on the Howth Road on October 8, 2008.

"I don't think justice was done properly," his mother said, as she left the court.

She was comforted by family members and her dead son's distraught girlfriend Michelle Finnegan.

Wilson was drinking a can of beer outside the supermarket before the attack, while waiting for a girl. He chased and killed Mr Howe, who had stolen €150 from the supermarket.

After his trial last October, a jury acquitted him of murder but found him guilty of manslaughter. Wilson had said in garda interviews that he never meant to kill anyone and only stabbed Mr Howe "to calm him down".

Members of Mr Howe's family openly wept as the dead man's sister, Rachel McCabe, read a victim impact statement to the court.

Defence counsel Brendan Grehan read out an apology from Wilson. It read: "I would like to apologise to Mr Howe's family. I know they must hate me."

Mr Grehan asked the court to take into account Wilson's young age when imposing a sentence.

Mr Justice George Birmingham said it was a desperately sad business, the effects of which would last forever. He said he had a sense of the enormity of what was involved after listening to the impact statement read aloud to the court.

The judge said a very significant fact was that the fatal weapon was not brought to the scene by Wilson, nor did he leave the scene to arm himself.

The knife was brought to the scene by the raiders. This distinguished the case from other knife crimes, he said.

However, he said, the sheer ferocity of the attack was alarming. He took into account the fact that a plea of manslaughter had been offered, that Wilson was a young man at the time of the incident and that he had a number of previous convictions.

He imposed a sentence of five years' imprisonment to date from October 14, 2010, the date of conviction. The trial took eight days in the Central Criminal Court, during which the jury was shown CCTV footage from SuperValu on the night of the killing. It showed the dead man and another man threatening female cash attendants with knives before fleeing the store.